208 Peach-Growing 



An injury still less severe but one that may cause much 

 alarm is when the heart- wood of the tree is killed entirely; 

 the outer surface of the wood is discolored, turning brown 

 or blackened, but the bark and cambium remain intact. 

 On cutting through the bark the discoloration is easily 

 detected. On the strength of this evidence many trees 

 following a "test winter" have been rooted up; but again 

 experience has shown that such trees usually make a good 

 recovery and under favorable conditions produce abundantly 

 for a considerable period thereafter. The cambium develops 

 a layer of sound wood over the dead interior. While such 

 trees are not as strong as normal trees and may break down 

 badly under stress of storms or weight of fruit, they should 

 not be destroyed following the injury on the supposition that 

 they are worthless, unless for other reasons than the one in 

 question. 



It is in the skillful pruning of winter-injured trees that 

 much of their future value lies. Eustace found that vigorous 

 trees not over five years old when badly injured made an 

 excellent recovery when the limbs were heavily cut back to 

 comparatively short stubs, but when older trees were similarly 

 pruned it proved fatal. Though they started a new growth, 

 they died almost invariably before the end of summer. On 

 the other hand, when the older trees were only moderately 

 cut back, they made a good recovery, very much better than 

 where no cutting back was done. 



These results largely confirm those of Waugh,^ also observa- 

 tions recorded in Michigan^ which indicate that cutting back 

 into wood i to f of an inch in diameter gave much better 

 results both in vigor of growth and in the foliage than either 



1 Mass. Hatch Exp. Sta. Repts. for 1904 and 1905. 



2 Mich. Exp. Sta. Bull. 177, 178, and Special Bull. 11. 



